The best known island off Tanzania is Zanzibar, but the coast also holds Pemba, Mafia, and a scatter of smaller islets and sandbanks worth a visit. Visitors come for white sand beaches, coral reefs, snorkelling, and the chance to swim beside whale sharks in season. These islands sit in warm Indian Ocean water off the mainland, and each one suits a different kind of trip.
This guide walks through the main islands and the smaller ones worth knowing about, what each is known for, how you actually get to them, and how a few days on an island fits with time spent watching wildlife on the mainland. If you already have safari plans, the coast is the natural second half of the trip.
The Zanzibar Archipelago: Unguja, Pemba and the Spice Island Name
The group of islands that most people picture when they think of the Tanzanian coast is the Zanzibar Archipelago. It sits in the stretch of ocean once called the Sea of Zanj, and it earned the old Spice Islands nickname from the clove, cardamom and cinnamon farms that still grow across its soil. Three islands in the wider region carry permanent towns and villages: Unguja, Pemba and Mafia. Unguja and Pemba make up the Zanzibar half; Mafia sits on its own further south.
Unguja is the one nearly everyone means when they say Zanzibar. It is the largest and most developed island of the group, with the widest choice of hotels, the most beaches, and the cultural heart of the coast at Stone Town. Pemba lies about 50 kilometres north of Unguja and feels like a different world, greener, hillier and much quieter, with farms of cloves covering the higher ground. Together they give you two very different island moods within a short flight of each other.
If your time is short, Unguja alone covers beach, history and a spice tour in a few days. If you have longer and want quiet, add Pemba or swap Unguja for it entirely.
Unguja: Stone Town, Spice Tours and the Northern Beaches
Unguja packs a lot into a small island. The obvious base is Stone Town, a UNESCO World Heritage site of narrow lanes, carved wooden doors and buildings that blend African, Arab, Indian and European influence over centuries of trade. You can spend a morning walking the old streets, visit the former slave market site, and watch the evening food stalls open at the waterfront gardens. The town works well as a first stop before you head to the coast for beach days.
A spice tour is the classic Unguja half day. The island grew rich on spice, and a working farm lets you taste and smell turmeric, cardamom, cinnamon, black pepper, cloves and nutmeg straight from the plant. It is a simple outing that explains the whole history of the place in an hour or two.
For sand, the north of the island holds the best of the wide beaches. Kendwa has a long flat stretch that stays swimmable at low tide, which is not true everywhere on Zanzibar because of the strong tidal range. Nungwi, next door, is shaped by rocky points that break the shore into smaller coves and holds most of the dive shops and boat operators. The east coast beaches like Paje and Jambiani draw the kite surfers when the wind is up. If you want a full rundown of the sand itself, our guide to Tanzania beaches covers which coast suits which kind of trip.
Diving and Snorkelling the Zanzibar Reefs: Mnemba Atoll
Off the northeast corner of Unguja sits Mnemba Atoll, a near perfect ring of reef around a tiny private island. It is the most popular snorkelling and diving spot on Zanzibar, known for clear water, wide coral fields and easy fish life. Moorish idols, surgeonfish, snappers and anemonefish are all common sightings over the coral. Boats run out to the atoll mainly from Nungwi and from Muyuni pier, and the pier route reaches the snorkelling ground in about twenty minutes.
The catch is that Mnemba is busy. It is the most visited reef on the island and dozens of boats arrive every day, so an early start makes a real difference to how the water feels. The atoll surrounds a private island that is closed to day visitors, so the reef itself is the attraction rather than the beach.
Chumbe Island: A Protected Coral Reef Off Stone Town
South of Stone Town lies Chumbe Island, a small privately run reserve that shows what a fully protected reef looks like. The coral park holds over 200 species of hard coral and more than 500 species of tropical fish, with butterflyfish, angelfish and the occasional ray or turtle over the coral. Because the number of visitors is capped, the water stays calm and the reef stays healthy in a way that busier sites cannot match.
A day guest package covers the boat transfers from the mainland, lunch, a guided snorkel over the protected reef, forest and mangrove walks, and a look at the old lighthouse and visitor centre. It is the kind of outing that suits people who care more about the state of the coral than about a party on the sand.
Mnemba Atoll gives you the classic Zanzibar snorkel with the most fish and the most boats. Go early.
Chumbe Island trades crowds for a strictly protected reef and a quiet, capped day trip near Stone Town.
Pemba Island: The Green Island and Its Coral Walls
Pemba is the archipelago’s quiet half. Locals call it the Green Island because it is hillier and more fertile than Unguja, with small farms covering the slopes and large clove plantations scattered across the higher ground. Tourism here is light. There are far fewer hotels, the roads are rougher, and the pace is slow, which is exactly why some divers prefer it.
The draw at Pemba is the diving. The island is ringed by steep coral walls that drop into deep channels, and the currents that run through those channels feed some of the healthiest reefs on the coast. This is drift diving territory, better suited to divers with a little experience than to first timers. The visibility is often excellent and the wall dives have a wild feel that the shallower Zanzibar reefs do not. If you want an island stay that is about the water and the quiet rather than beach bars, Pemba is the pick.
Mafia Island: Marine Park, Coral and Whale Sharks
Mafia sits on its own about 100 to 160 kilometres south of Zanzibar, just beyond the mouth of the Rufiji River. It has long been the choice of people who want laid back island living with excellent snorkelling and scuba diving and none of the crowds. Tanzania set up its first marine park here in 1995, and the protected water shelters some of the healthiest coral reefs in East Africa. Divers count over 50 types of coral and around 400 species of fish inside the park.
The dives at Mafia are more demanding than the gentle reefs of Zanzibar because of strong tides and currents, but those same currents carry the nutrients that make the marine life so rich. Your chances of seeing something large, a shark, a ray, a turtle, are higher here than around Unguja.
The headline event is the whale sharks. Between roughly October and March, plankton rich water flowing south from the Rufiji River draws whale sharks close to Mafia’s shore, and you can snorkel beside them. The prime window for the calmest water and the best sightings runs from about November to January. These are gentle filter feeders, and swimming next to one is the reason many divers put Mafia at the top of their list. Popularity has brought some pressure, and crowding around the sharks is a real conservation worry, so it pays to choose an operator that keeps its distance and limits swimmer numbers.
Zanzibar is the island you visit for the town and the sand. Mafia is the island you visit for the water and the whale sharks.
Smaller Islets and Sandbanks Worth a Day Trip
Beyond the three main islands, the coast holds a set of small islets and sandbanks that make good half day or full day trips. None of them need an overnight stay. They slot into a wider island holiday or even a spare day at the start of a mainland trip.
Prison Island, properly called Changuu, sits a short boat ride from Stone Town. It was built as a detention site and later a quarantine station, and today it is a calm spot known for its colony of giant Aldabra tortoises, some over a hundred years old. It pairs naturally with a Stone Town and spice tour day.
Bongoyo Island lies about 3 kilometres off Dar es Salaam and is the most visited of the small reserve islands near the city. A boat runs out in about thirty minutes from the Msasani slipway, and it makes an easy escape if you have a day to spare in Dar before or after a flight. The water is clear and the beach is quiet on weekdays.
Down the coast near Kilwa Masoko, the islands of Kilwa Kisiwani and Songo Mnara hold a different kind of draw. These are UNESCO listed ruins rather than beach islands. At its height in the 14th century Kilwa Kisiwani was the most important trading centre on the East African coast, and its ruins include mosques, an Omani fort and the remains of a great palace. Songo Mnara, reached by dhow from the mainland, holds a palace complex, houses and mosques inside a defensive wall. You reach them by boat transfer from Kilwa Masoko, and the best months for a visit run from June to September.
How to Reach the Islands Off Tanzania
Getting to the islands is straightforward, and in most cases you have a choice between a short flight and a slower boat.
For Zanzibar (Unguja), the fast ferry from Dar es Salaam runs several times a day to Stone Town, with morning, midday and afternoon departures. Many visitors instead fly straight into Zanzibar’s airport from the mainland or on an international connection, which skips the port entirely. If you are arriving from further afield, the practical points on entry, visas and paperwork in our note on travel to Zanzibar are worth a read before you book.
For Pemba, light aircraft fly from Dar es Salaam several times a day, with the hop taking about an hour. Ferries also connect to Zanzibar City a few times a week, and from there you can fly the short leg onward to Pemba. The flight is the simplest option by a wide margin.
For Mafia, the fastest and most reliable route is a light aircraft from Dar es Salaam, a flight of roughly 30 to 40 minutes. Budget travellers can instead take the government ferry from the mainland at Nyamasati, reached by local minibus from Dar, though it is a much longer and rougher way in. There are also short direct flights between Mafia and Zanzibar, which makes it easy to combine the two islands in one trip.
Pairing an Island Stay With a Mainland Safari
The best reason to think about the islands early is how well they pair with the wildlife side of a Tanzania trip. The classic shape of a two week holiday is a run of game drives in the north followed by a few days on the coast to slow down. After long dawn starts and dusty tracks, an island is where you rinse off the safari and do nothing for a while.
The logistics fit neatly. Most northern circuit trips end back near Arusha or Kilimanjaro, and there are regular flights from there to Zanzibar, so you can go from a morning game drive to an afternoon on the sand in the same day. If your wildlife plans run through the southern parks instead, Mafia is the natural coastal partner because both sit in the south and share light aircraft routes. To see how the two halves connect, our overview of a Tanzania safari lays out the main circuits and where the coast fits at the end.
The season matters when you plan the pairing. The long dry months from June to October are the strongest for wildlife viewing in the north and also give reliable beach weather, which is why that window is the busiest. If you are set on whale sharks at Mafia, aim for the late months of the year into January, and build the safari around that fixed date rather than the other way round.
Book the island as the second half of the trip, not the first. Ending on the coast means you are not rushing back to a game reserve with sand still in your bag.
Choosing the Right Island for Your Trip
If you want one island that does a bit of everything, choose Unguja. It has the town, the history, the spice tour, the wide northern beaches and easy access to Mnemba and Chumbe for snorkelling. It is the safe pick for a first coast visit and for families who want variety within a short drive.
If you want quiet and serious diving, choose Pemba. The wall dives and drift channels reward divers with some experience, and the light tourism means you share the reefs and the villages with very few other visitors.
5-Day Arusha, Lake Manyara, Tarangire & Ngorongoro Safari
9-Day Grand Northern Circuit Safari
6 Days Lake Manyara, Serengeti & Ngorongoro Crater
If you want the marine park and the whale sharks, choose Mafia. It is the most relaxed of the three, the reefs inside the park are among the healthiest on the coast, and nowhere else on the Tanzanian shore gives you the same chance to snorkel beside whale sharks in season.
And if you only have a spare day rather than a week, the small islets deliver. Prison Island and its tortoises, Bongoyo off Dar, or the old stone ruins at Kilwa each give you a taste of the coast without the commitment of a full island stay.
Frequently Asked Questions
Which island off Tanzania is best for a first visit?
Unguja, the main Zanzibar island, is the easiest first choice. It has the widest range of hotels, the cultural draw of Stone Town, the classic spice tour and the best of the wide northern beaches, plus quick access to snorkelling at Mnemba and Chumbe. It suits couples, families and solo travellers alike, and it is the simplest island to reach and get around.
Where can I swim with whale sharks in Tanzania?
Mafia Island is the main whale shark spot. The animals gather close to shore from about October to March when plankton rich water flows south from the Rufiji River, and the best window for calm water and reliable sightings is roughly November to January. Choose an operator that limits swimmer numbers and keeps a respectful distance, as crowding around the sharks has become a genuine conservation concern.
How do I get from the mainland to the islands?
Zanzibar is reached by fast ferry from Dar es Salaam several times a day, or by a short flight. Pemba is served by light aircraft from Dar in about an hour, plus a few weekly ferries by way of Zanzibar City. Mafia is best reached by a 30 to 40 minute flight from Dar, with a cheaper but much slower government ferry from Nyamasati for budget travellers. Short flights also link Mafia directly with Zanzibar.
How much does an island stay off Tanzania cost?
Costs range widely. A one way flight from Dar es Salaam to Pemba or Mafia runs around 150 US dollars, while the Dar to Mafia government ferry is closer to 8 dollars for those willing to travel rough. A capped day trip to Chumbe Island near Stone Town sits around 90 dollars per person including boat transfers, lunch and a guided snorkel. Hotels span simple guesthouses on Pemba and Mafia up to high end lodges, so total spend depends far more on where you sleep than on how you travel.
Is Pemba or Mafia better than Zanzibar?
It depends on what you want. Zanzibar has the most to see and do and the easiest access, so it wins for variety and convenience. Pemba is quieter and greener with world class wall diving for those with some experience. Mafia is the most laid back, with a protected marine park and the whale shark season. Many divers rate Pemba and Mafia above Zanzibar precisely because they are less developed, but Zanzibar remains the stronger all round choice for a mixed trip.
Can I combine an island with a safari in one trip?
Yes, and it is the most popular way to plan a Tanzania holiday. Northern circuit safaris end near Arusha or Kilimanjaro with regular flights on to Zanzibar, so you can finish a game drive in the morning and be on the beach by afternoon. Southern park trips pair naturally with Mafia, since both sit in the south and share light aircraft routes. Put the island second so you end the trip resting on the coast.
